New install -- update

David Nadle

> Keep us posted! I am <BR>
> listening. <BR>

And I appreciate it! The times I quoted were for the very last section of the radiator to get hot, from the moment the thermostat called for heat. So it includes the 14 minutes to get from stone cold to steam-filled mains. Does it still seem slow to you?

I will check out the publication you mentioned.

David Nadle

First cold day...

...so I cranked up the thermostat at the top of the hour and started my stopwatch. If you recall, I'm the new Utica PEG112C with the funky 45 on the header, single loop mains, etc.

System was off all day and totally cold. Within 10 minutes steam was entering the mains and pushing air out the newly installed main vent. At 14 minutes mains were hot at every takeoff.

The average time for 7 radiators to get fully hot was 36 minutes. The fastest was also one of the furthest, a second floor bedroom 24 minutes. But its vent was set to its fastest setting.

I used the average and the percentage each radiator was fast or slow of it to tweak the air vent settings. For example, between 10-20% faster than average = down one notch. What do you think of that approach?

The only curiosity is that the radiator closest to the boiler didn't get hot at all, not even one section. Its vent was set pretty slow, however, because it's in the room with the thermostat.

That's enough "research" for tonight. Insulation arrives on Monday.

Brad White

Can you post pictures, David?

Sounds like progress- Even uninsulated though, I would still hope to get you steam to the radiators faster than that by maybe half. Optimist that I am. Burning a lot of fuel while you are waiting and all that.

Did you size the vents using Gerry Gill and Steve Pajek's tome, "Balancing Steam Systems Using a Venting Capacity Chart"? Available in the on-line store... I found it educational and helpful. A good reference for a good cause at a good price, and you can have it by e-mail too.

Keep us posted! I am listening.

Daniel_3

That timing for steam filled mains is pretty good. the filling of the main has much to do the venting and pressure limit. The best steam is "spread out" and unsaturated(dry). My mains 30 and 35 ft. a piece get filled in about 10 minutes at 1 psi with heat timer varivalves on the rads (some have two) and gorton #1's on the mains(longer main has a varivalve as well). 15 radiators get fully charged in about 30 minutes.

Dave_4

Pics

Brad,

I posted pics a while back, in this post:

http://forums.invision.net/Thread.cfm?CFApp=2&&Message_ID=353652&_#Message353652

Brad White

Thanks, David- I remember now

As for timing to fill the vents, I suppose it is a matter of what you used to have as a benchmark. You did say 37 minutes which to me seems a long time to wait while you are burning fuel.

Like the old saying when asked, "how is your wife?" you reply, "compared to whom?"

I used to own several steam systems (3-Deckers here in Boston back in the day) and wish I knew then what I know now- and even that is not enough sometimes.

For example, I had what had to be a poorly vented system serving the middle floor (my unit) and it took 35 minutes to warm the radiators including banging from too much pressure. I insulated the piping and that got the on-time to steam-at-radiators down to about 20-25 minutes, a major improvement.

I can only imagine if I had lower pressure and better venting, might I have cut this in half?

If a boiler has say a twelve gallon water content (100 lbs.) at 60 degrees starting temperature and 125 MBH input and 80% efficiency, you should be able to get that water to the boiling point (152 degree rise from 60 F to 212 F) in about nine minutes. (100 lbs. x 152 degrees = 15,200 BTUs which is 9.12 minutes worth at 100 MBH net output).

Every minute thereafter you are pumping in 100 MBH net, which is about 103 lbs. per hour or about 1.7 lbs. per minute ideally.

This volume of water (392.2 cubic inches of liquid) boiled into seam at low pressure (1700:1) would be over 385 cubic feet of steam per minute, enough to fill a lot of 2" pipe quickly. Naturally there is an ebb and flow, advance and retreat. But unless my math is off (as it may be), I had to wonder.

Just thinking out loud. I really do not have an answer specific to a given system, just as short as possible.

Dave_4

Math looks spot on

Brad,

I'm not sure how many gallons are in the PEG112C, but it took just 9 minutes to get to boil. Another 5 minutes and 75 feet of mains was hot. It seems to me the rad vents are slowing things down, to whatever extent the system is too slow. Depending on the venting rate there's a huge difference between first section hot and all sections hot. Based on my notes, the "steam at radiators" time is about 20-25 minutes.

Now, I'm sure I've read somewhere that slowing the rate the radiators fill is good for keeping things quiet. With the vents at their original settings, 3 of 8 radiators were fully hot within 30 minutes, and another 2 were mostly hot. After a few cycles of tweaking I'd be surprised if I can't get 6 or 7 radiators fully hot within 30 minutes.

Brad White

Whew....

Sometimes I wonder...

Overall it does sound faster when you explain it that way.

As far as your statement that the rad vents are slowing things down, to me that means that the main vents are not helping as they should. The radiator vents are doing more than just their volumes and those of their feeding run-outs, they are doing the main venting too, to a degree.

I am helping a friend with her steamer, not a bad install to be sure. I sized the vents for a two-minute venting at 2 ounces of pressure as a place to start. I built a "menorah" and can add or subtract vents if too fast or too slow.

Right now she waits what seems like an eternity to get hot radiators. That will be my new mental benchmark.

Yes, keep the updates coming. This is rather fun is it not? So few outside the trade understand this...

Dave_4

not sure about that

I think the main vent is doing the job. The mains are filling fast (about 4 minutes) and then it shuts.